Table 3.
Immunological Predictors of Clinical Severity for the Second Detected Infection
| Unstratified Analysis for Enrollment HI Profile |
Unstratified Analysis for Symptomatic or Subclinical Infection |
HI-negative at Enrollment |
Some Immunity at Enrollment |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HI-neg | HI-pos | Pa | Asx | Sx | P | Asx | Sx | P | Asx | Sx | P | |
| (N) | (39) | (84) | (89) | (33) | (22) | (16) | (67) | (17) | ||||
| Post-1st-detected infection | ||||||||||||
| Rise in summed HAI titers (Log10) | 2.86 | 2.59 | .051 | 2.70 | 2.59 | .381 | 2.96 | 2.73 | .288 | 2.62 | 2.46 | .311 |
| Total seropositivity (no. serotypes) | 3.72 | 3.87 | .138 | 3.88 | 3.67 | .163 | 3.77 | 3.64 | .689 | 3.91 | 3.71 | .283 |
| Pre-2nd-detected infection | ||||||||||||
| Summed HAI titers (Log10) | 2.10 | 2.40 | <.01 | 2.31 | 2.24 | .254 | 2.10 | 2.09 | .642 | 2.37 | 2.50 | .730 |
| Total seropositivity (# serotypes) | 3.10 | 3.67 | <.01 | 3.61 | 3.14 | .014 | 3.27 | 2.88 | .223 | 3.73 | 3.41 | .397 |
| Decay rate | ||||||||||||
| % decrease in summed titers from post-1st to pre-2nd detected infection by year | 54.7% | 26.1% | <.01 | 38.7% | 25.7% | .125 | 72.9% | 31.1% | .097 | 27.5% | 20.0% | .747 |
Abbreviations: DENV, dengue virus; HAI,hemagglutination inhibition assay; HI,hemagglutination inhibition; Asx, Asymptomatic (subclinical) second-detected DENV infection; Sx, symptomatic second-detected DENV infection.
a P values were obtained using non parametric Wilcoxon tests with SAS' NPAR1WAY procedure.